• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Homeostasis In Mammals.

Extracts from this document...


HOMEOSTASIS IN MAMMALS Homeostasis is method by which an organism controls it internal environment. It does this by keeping the level of a number of substances in the body at a constant level (at a set point). If levels of substances move away from that set points then corrective mechanisms take place which restore the level to the set point. In this essay I am going to talk about three types of Homeostasis, these are: glucose regulation, osmoregulation and thermoregulation. Glucose regulation is simply the regulation of the level of glucose in the blood. Thee amount of glucose in the blood is commonly referred to as the blood sugar level. A rise in the blood sugar level (caused, for example by eating a meal) will be detected by the pancreas and the insulin-producing tissue, called the islets of Langerhans release the hormone called insulin, this causes increased absorption of glucose by cells, due to the increased permeability of cell membranes. ...read more.


to become more permeable to water. Because of this more water is reabsorbed into the blood and the level of water in the blood rises. This process works both ways. If the level of water is too high within the body ADH will not be released into the blood causing little re-absorption of water into the blood this causes a dilute urine to be produced, where as a concentrated urine will be produced if there are high levels of ADH in the blood. Thermoregulation is the method by which animals control their internal body temperature. Animals fall into two categories where this is concerned: ectotherms or endotherms. Ectotherms, use external sources of heat, e.g. the sun to raise or maintain there body temperature. Reptiles such as lizards and snakes can often be seen basking in the sun on rocks in order to achieve this control over their body temperature. This method of thermoregulation is not very reliable in some cases as there may be factors that limit the ability of ectothermic animals to regulate their body temperature. ...read more.


In the case of mammals needing to reduce their heat levels (in hot conditions) vasodilatation occurs, this is the opposite of vasoconstriction, blood vessels become wider allowing more blood to flow through, closer to the surface of the skin, thus allowing heat to be lost through the skin due to radiation. Sweating is another method used; the evaporation of water from the skin has a cooling effect on the body. This effect is due to a physical principal. To convert water to a vapour a certain amount of heat is required this is called the heat of vaporization. This heat will increase the speed at which the water molecules move, causing them to escape into the air and cool us down in the process. These mechanisms are mainly controlled by the hypothalamus, which contains temperature receptors that are sensitive to the temperature of the blood. It is this part of the brain that controls mostly all of the homeostasis in mammals. Charles Thompson 5/7/07 ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Exchange, Transport & Reproduction section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Exchange, Transport & Reproduction essays

  1. Marked by a teacher

    What is Type 1 diabetes

    3 star(s)

    The diet should also include daily portions of fresh vegetables and fibre. The patient must measure their blood sugar very regularly in order to decide if the prescribed treatment is helping. The patient should also consult a diabetologist who has a joint clinic with a specialist obstetrician to monitor the diabetes and the baby's progress carefully during pregnancy.

  2. Marked by a teacher

    Effect of temperature on membranes

    3 star(s)

    researchers who intend to isolate vacuoles as the red colourings make it easier to distinguish the vacuoles from the other contents of the cells. The red-violet vesicles obtained from the protoplasts of beetroots are intact beet vacuoles. In order for betalain pigment to exit the cell, the pigment molecules would

  1. heart essay

    The formula for finding the cardiac output is: Cardiac Output = Heart rate X Stroke volume or (CO = HR X SV). So if a person had a resting heart beat of 72 BPM and a stroke volume of 70ml then the resting cardiac output would be calculated as follows:

  2. The Skeletal and Muscular System

    Examples are the shoulder and hip joints. These joints allow movement in all directions or in three planes. b. Hinge Joint. They consist of one convex surfaced bone that fits into another concave surfaced bone. Examples are the knee and elbow joints.

  1. permeability of beetroot membranes

    We recorded the weight of the groups before and after they were put into the solutions and we then worked out the change in mass as a percentage of their original masses. My Preliminary Results Concentration of glucose solution (M)

  2. What is Homeostasis?

    The rat consequently ate far more than it would usually have done. This study showed that the presence of food in the mouth is not enough alone to regulate food intake. The taste of food is sensed by taste receptors on the tongue and the information is then passed on to the brain.

  1. Diabetes Mellitus

    * Glucagon increases the liver's ability to make glucose from other compounds, such as amino acids. As with insulin, the most important factor that controls the release of glucagon from the pancreas is the blood glucose level. As blood glucose rises, glucagon output falls and vice versa.

  2. Revision questions on Communication, Homeostasis and Energy

    * Remain inactive. * Spread out limbs to increase surface area to lose heat from. * Less sweat secreted so less evaporation of water. * No panting so less evaporation of water. * Raised hairs on skin to trap a layer of insulating air.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work